[davidmor]

I have an Opel 2.4L engine and need to replace the intake valves. Opel GT Source has been waiting months to get some out of Germany, but I am hoping somebody here might have a suggestion.

Size 45mm end diameter, 9 mm valve stem, and 4.860" height. This has a singe groove in the top.

If this size is impossible to find, what about a new valve guide insert with a different valve size?

Thanks,
Dave

 

[GTJIM (R.I.P.)]

45mm valves

Can you say Small Block Chevy?

45mm = 1.77" so 1.84" Chevy intakes have a usable head size.
Their stem is 11/32" (=8.73mm) which is too small for the Opel
valve guides but that can be rectified by installing a K-Line
bronze insert - just like they use to recondition Chevy valve guides! The head needs to be carefully squared up and the insert fitted in line with the seat so not to much metal needs to be removed from the seat to get it all OK again.

There are many different spring caps to fit the several different Chevy springs around - one of them is sure to be close to what is needed to mate to your 2.4 litre springs. The 2.4 springs are the same on both valves, I think, and not like the earlier 1.9 heads which have different intake and exhaust springs to allow for the exhaust rotator.

Just check that the Chevy valves are not too long. Though it is possible to get custom length valves made. Even possible to turn the valve stem ends to take Opel locks and spring caps.
Find a good cylinder head shop that does work for race cars and you will have more luck with getting non-stock stuff done.